Flat plate antenna module

Abstract

An antenna module for use a non-conductive cab of a motor vehicle includes a dielectric substrate and one or more antenna loops arranged on the substrate. The substrate is adapted to be installed between the headliner of a cab and the dielectric roof. The module may include a CB antenna loop, an AM/FM antenna loop, a cellular mobile telephone antenna loop, and a global positioning system antenna, without the need for any antenna structure external to the cab. The antennae are arranged on the module in a nested configuration. A CB antenna, provided with loading coils, forms an outer loop. An AM/FM antenna loop, including a capacitor yielding a substantially short circuit connection in the FM frequency range, forms a FM frequency antenna loop and an AM frequency dipole, within the CB loop. A multiloop array cellular telephone antenna is arranged within the AM/FM loop. A standard crossed dipole GPS antenna is positioned in an area between the CB loop and the AM/FM loop near one corner of the substrate. Coaxial antenna feedlines connected to the various antennae are routed through cab support posts to associated electronic circuitry in the cab.

What we claim is: 
     
       1. A planar antenna module for installation under a dielectric cover of a vehicle, comprising: a dielectric substrate;   a mobile telephone antenna loop for transmission and reception of mobile cellular telephone signals and comprising a plurality of conductor sections on the substrate forming a substantially square loop having a perimeter of an electrical length approximately equal to two wavelengths of a signal in the frequency range of cellular telephone signals, the conductor sections at each corner of the square loop forming four separate loading capacitors, the conductor sections forming the capacitors adapted to be shortened to optimize the antenna effectiveness when installed in the proximity of dielectric covers of differing dimensions and dielectric characteristics; and   conductor sections disposed on the substrate forming a substantially square AM/FM antenna loop surrounding the mobile telephone antenna loop, the AM/FM antenna loop comprising a pair of conductor sections of substantially equal length and a capacitor, each conductor section having one end connected to an antenna feed line and another end connected to one side of the capacitor, the capacitor having a predetermined value of capacitance such that the capacitor presents a substantially short circuit at FM frequencies.   
     
     
       2. The antenna module in accordance with claim 1 and further comprising conductor sections disposed on the substrate forming a substantially square CB antenna loop surrounding the AM/FM antenna loop for transmission and reception in the CB frequency range, the CB antenna loop comprising a plurality of antenna coils connected between certain of the conductor sections of the CB loop to provide an effective electrical length of the CB loop equivalent to one wavelength in the CB frequency range. 
     
     
       3. The antenna module in accordance with claim 2 wherein the mobile telephone antenna loop is connected to a first antenna feed line and the AM/FM antenna loop is connected to a second antenna feed line and the CB antenna loop is connected to a third antenna feed line and wherein the second and third antenna feed lines are connected to the respective antenna loops near one portion of the substrate. 
     
     
       4. The antenna module in accordance with claim 3 and further comprising a crossed dipole GPS antenna disposed in a area of the substrate extending between a portion of the CB antenna loop and a portion of the AM/FM antenna loop. 
     
     
       5. The antenna module in accordance with claim 4 wherein the GPS antenna is connected to a fourth antenna feed line and wherein the module is installed under the dielectric roof of a motor vehicle having support posts at adjacent corners of the roof and wherein the first and second and third antenna feed lines are routed along one of the support posts to associated electronic equipment and the fourth antenna feed line is routed along the other of the support posts to associated electronic equipment. 
     
     
       6. The antenna module in accordance with claim 3 wherein the substrate comprises a flexible sheet of dielectric material. 
     
     
       7. The antenna module in accordance with claim 6 wherein the substrate is a sheet of fiberglass. 
     
     
       8. The antenna module in accordance with claim 6 wherein the substrate comprises a sheet of Kapton. 
     
     
       9. The antenna module in accordance with claim 6 wherein the flexible sheet has a thickness in the range of 0.010 to 0.050 inches. 
     
     
       10. The antenna module in accordance with claim 1 wherein the antenna module is installed under the dielectric roof of a vehicle and the dielectric roof has a thickness in the range of 0.075 to 0.400 inches. 
     
     
       11. The antenna module in accordance with claim 10 wherein the dielectric roof has a dielectric coefficient in the range of 2.0 to 5.0. 
     
     
       12. The antenna module in accordance with claim 1 wherein the conductor sections each comprise copper strip having a width in the range of 0.050 to 0.200 inches. 
     
     
       13. A planar antenna module for installation under a dielectric cover of a vehicle, comprising: a dielectric substrate;   a mobile telephone antenna loop for transmission and reception of mobile cellular telephone signals and comprising a plurality of conductor sections on the substrate forming a substantially square loop having a perimeter of an electrical length approximately equal to two wavelengths of a signal in the frequency range of cellular telephone signals, the conductor sections at each corner of the square loop forming four separate loading capacitors, the conductor sections forming the capacitors adapted to be shortened to optimize the antenna effectiveness when installed in the proximity of dielectric covers of differing dimensions and dielectric characteristics;   the mobile telephone antenna loop comprising an array of four individual, substantially square antenna loops, each of the individual loops having sides of an electrical length equivalent to one quarter of one wavelength of the signal in the frequency range of cellular telephone signals.   
     
     
       14. The antenna module in accordance with claim 13 wherein the conductor sections each comprise a copper strip having a width in the range of 0.050 to 0.200 inches and wherein adjacent conductive strips are separated by a distance in the range of 0.100 to 0.400 inches. 
     
     
       15. The antenna module in accordance with claim 14 wherein the substrate comprises a flexible sheet of dielectric material having a thickness in the range of 0.010 to 0.050 inches. 
     
     
       16. The antenna module in accordance with claim 15 and installed under a dielectric roof of a motor vehicle having a thickness in the range of 0.075 to 0.400 and having a dielectric coefficient in range of 2.0 to 5.0. 
     
     
       17. The antenna module in accordance with claim 13 and wherein each of the individual loops has outer perimeter sections forming a part of the perimeter of the mobile telephone antenna loop and wherein current flow in adjacent outer perimeter sections of adjacent ones of the individual loops is in a the same direction. 
     
     
       18. An antenna module comprising: a planar dielectric substrate adapted to be installed between the headliner of an automotive vehicle and a dielectric roof;   a pair of electrical conductors sections and a capacitor disposed on the substrate, each conductor section having one end connected to an antenna feedline and another end connected to one side of the capacitor and forming a substantially square antenna loop;   each side of the loop having an electrical length approximately equal to one wavelength at a frequency in the FM frequency range and the capacitor having a value of capacitance such that the capacitor presents an essentially short circuit in the FM frequency range and a substantial impedance in the AM frequency range, whereby the capacitor provides a substantially short circuit connection in the FM frequency range and a significant impedance value in the AM frequency range providing a loop antenna in the FM frequency range and a dipole antenna in the AM frequency range.   
     
     
       19. The antenna module in accordance with claim 18 and further comprising a mobile telephone antenna loop for transmission and reception of mobile cellular telephone signals and comprising a plurality of conductor sections on the substrate forming a substantially square loop having a perimeter of an electrical length approximately equal to two wavelengths of a signal in the frequency range of cellular telephone frequency signals. 
     
     
       20. The antenna module in accordance with claim 19 and further comprise a crossed dipole GPS antenna disposed in an area of the substrate extending between a portion of the CB antenna loop and a portion of the AM/FM antenna loop. 
     
     
       21. The antenna module in accordance with claim 20 and further comprising conductor sections disposed on the substrate forming a substantially square CB antenna loop surrounding the AM/FM antenna loop for transmission and reception in the CB frequency range.